The On-Line Encyclopedia of Integer Sequences (OEIS)

Revision History for A098372 (Bold, blue-underlined text is an addition; faded, red-underlined text is a ~~deletion~~.)
Showing entries 1-10 | older changes

A098372

a(n) = Max_{k=1..n-1} gcd(n, A098371(k)).
(history; published version)

#17 by Susanna Cuyler at Wed Mar 31 20:26:34 EDT 2021

STATUS

proposed

approved

#16 by Antti Karttunen at Tue Mar 30 15:11:25 EDT 2021

STATUS

editing

proposed

#15 by Antti Karttunen at Tue Mar 30 12:33:32 EDT 2021

KEYWORD

nonn,look,changed

#14 by Antti Karttunen at Tue Mar 30 11:58:58 EDT 2021

LINKS

Antti Karttunen, <a href="/A098372/b098372.txt">Table of n, a(n) for n = 1..8192</a>

#13 by Antti Karttunen at Tue Mar 30 11:56:45 EDT 2021

COMMENTS

but this generates terms that differ from ones in the data section at least at n=14, 26, 38, 74, etc106.

Also, the The original author also commented also that: A098371(n) = #{k: a(n) = gcd(n, A098371(k))}, but please see my notes in that sequence.

LINKS

Antti Karttunen, <a href="/A098372/a098372.txt">Data supplement: n, a(n) computed for n = 1..65537</a>

#12 by Antti Karttunen at Tue Mar 30 11:13:28 EDT 2021

COMMENTS

Also, the original author commented also noted that: A098371(n) = #{k: a(n) = gcd(n, A098371(k))}, but please see my notes in that sequence.

but please see my notes in that sequence also.

#11 by Antti Karttunen at Tue Mar 30 11:08:27 EDT 2021

NAME

a(n) = Max_{k=1..n-1} gcd(n, A098371(k)).

COMMENTS

From Antti Karttunen, Mar 30 2021: (Start)

A098371The original definition was: a(n) = #Max_{k: a(=1..n) = } gcd(n, A098371(k))}.

but this generates terms that differ from ones in the data section at n=14, 26, 38, 74, etc.

Also, the original author also noted that: A098371(n) = #{k: a(n) = gcd(n, A098371(k))}.

but please see my notes in that sequence also.

(End)

EXTENSIONS

Definition corrected to match with the data. - Antti Karttunen, Mar 30 2021

#10 by Antti Karttunen at Tue Mar 30 10:21:47 EDT 2021

PROG

(PARI) A098372list(up_to) = { my(v=vector(up_to), y=vector(up_to)); v[1] = 1; y[1] = 1; for(n=2, up_to, my(m=1); for(k=1, n-1, m = max(m, gcd(n, v[k]))); y[n] = m; v[n] = sum(k=1, n-1, m == gcd(n, v[k]))); (y); }; \\ Antti Karttunen, Mar 30 2021

STATUS

approved

editing

Discussion

Tue Mar 30

11:04

Antti Karttunen: Note that the PARI-program implemented by the original definition:
A098372list(up_to) = { my(v=vector(up_to),y=vector(up_to)); v[1] = 1; y[1] = 1; for(n=2,up_to,my(m=1); for(k=1,n-1,m = max(m,gcd(n,v[k]))); v[n] = sum(k=1,n-1,m == gcd(n,v[k])); y[n] = max(m,gcd(n,v[n]))); (y); };

11:04

Antti Karttunen: gives terms: 1, 1, 1, 2, 1, 2, 1, 4, 3, 2, 1, 6, 1, 7, 5, 4, 1, 6, 1, 10, 7, 2, 1, 12, 5, 13, 9, 7, 1, 10, 1, 16, 11, 2, 7, 18, 1, 19, 13, 10, 1, 14, 1, 22, 15, 2, 1, 16, 7, 10, 3, 13, 1, 18, 11, 28, 19, 2, 1, 30, 1, 2, 21, 16, 13, 22, 1, 4, 23, 14, 1, 36, 1, 37, 15, 19, 11, 26, 1, 40, 27, 2, 1, 42, 5, 2, 29, 22, 1, 30, 13, 46, 3, 2, 19, 48, 1, 14, 33, 20, 1, 6, 1, 52, 35, 53, 1

11:06

Antti Karttunen: that differ from the terms in the data section at n = 14, 26, 38, 74, 106, ...
So I will change the definition to match with the data.

#9 by Joerg Arndt at Mon Oct 21 02:20:55 EDT 2019

STATUS

proposed

approved

#8 by Michel Marcus at Mon Oct 21 01:10:40 EDT 2019

STATUS

editing

proposed